Robotic Fish - Computerphile

Key Takeaways

technically his name is Gilbert with two L's yeah right now it doesn't even have the googly eyes on it so that's why it's not working I think that's probably it I'm stepen how I'm a fourth year PhD student um in the biomimicry program and I study fish biomechanics so um I'm interested in how they move um and how their body movements uh relate to their um total body so this is are um fish robot it's a robotic platform that we use to answer questions about fish Locomotion that we can't with light fish cuz robots do what you want whereas the animal doesn't always do what you ask it to and so um the robot actually provides this an interesting set of um circumstances we can change the shape of the robot independent of the Motions that the body makes so if I'm studying eels and tuna um I can't tell the eel would you mind swiming like a tuna for me and vice versa whereas with a robot we can make this shaped like a tuna and say robot please swim like an eel so there's a skeleton inside that you can then have algorithms yeah the robot is pretty simple it's five Servo Motors connected through an Arduino and then we use the Arduino program to um run the robot and um the program that we've written allows us to program uh straight swimming but also interject turns whenever we want um and this is based on some of my earlier research with Fish And understanding how they control their pulses so the tether it's slightly taking it for wall right so yeah um there's no sensors or anything in here um deciding when it should turn it's just a pre-programmed algorithm and um I use the tether kind of as a leash to reset the system looks like we have a motor not behaving everything on this robot save the um Motors and the wires is 3D printed so that flexible tail you see we printed in our machine in the back and these body shells we copied the morphology of an actual fish so this is based on a giant Danio which um is the larger cousin of the zebra fish that you see in the pet shop all the time we can make this shape like anything our um future research is going to involve looking at um how increasing body depth uh changes the maneuverability so think about uh plate-shaped fish like a discus or um like a place or a skate or well places and skates are interesting because um they've turned their heads to the side and so they look like they're um top to bottom um but they do swim like a laterally compressed fish but um think more like uh tangs like Dory hi I'm Dory where which way I'm trying to see which motor this is and I'll just unplug it sounds like it's complaining yeah no that didn't drop the amperage okay there's a few different applications mainly opportunities for underwater reconnaissance it can be applied to I mean the Navy would be interested in things like this but so would um uh oil rig um inspections as well as dams or Bridges um most often uh the robots that using right now are shaped like refrigerators and have about six squirt guns pointing off of uh several different directions and so you can imagine Jets yeah you've got a very un hydrodynamic shape that's very unstable matched with a very complicated control scheme and so you lose these things all the time and they're like $5 million a piece so if you have a control scheme that's more robust but is still just as maneuverable um you can potentially not lose things nearly as often so we hope yeah yeah um but the other thing is like just underwater exploration in general like uh we can scuba dive and free divers can dive down to like 500 ft but they can only be down there for 3 to 40 minutes depending on uh the circumstances and so because of that we know almost nothing about what's happening underwater ultimately it would be good if we can spend a whole lot more time underwater and uh drones like this are going to be important for being able to expand our capabilities in that realm so just a single wave uh we're working on more complex implementations and finally it can even perform something called concertina Locomotion and so once it gets to that point it'll finish a cycle so this is what they do inside of a tunnel if it hit the tunnel wall it would be detecting that